Range finder device and camera

ABSTRACT

A range finder device, for measuring, when a plurality of projected lights having radiation patterns whose light intensity differs three-dimensional space-wise are irradiated onto an object from a light source on a time-sharing basis to image-pick up reflected light of the projected light from the object with a camera, a distance using the light intensity of an image picked up, characterized in that, with respect to each of a plurality of surfaces including the center of the light source and the center of a lens, there is obtained, in advance, relation between an angle of each projected light from the light source and light intensity ratio in each surface, characterized in that, at the time of actual distance measurement, light intensity of each pixel of the camera is measured, and on the basis of the light intensity thus measured, and relation between the angle and the light intensity ratio on a predetermined surface corresponding to a coordinate position of the pixel measured, there is obtained the angle corresponding to the light intensity of the predetermined pixel thus measured, and characterized in that, on the basis of these light intensity measured, the angles obtained and further two-dimensional coordinate position information on the predetermined pixel on the image, a distance to the object is calculated.

TECHNICAL FIELD

[0001] The present invention relates to a range finder device formeasuring a three-dimensional shape of an object.

BACKGROUND ART

[0002] As a range finder device for performing three-dimensional shapemeasurement based on triangulation of projected light and an observedimage, such a real-time operable range finder device as shown in, forexample, FIG. 40 has been proposed.

[0003] In FIG. 40, reference numerals 101A and 101B denote laser lightsources having slightly different wavelength; 102, a half mirror forsynthesizing laser light from the laser light sources having thedifferent wavelength; 103, a light source control part for controllinglight intensity of the laser light source; 104, a rotary mirror forscanning laser light; 105, a rotation control part for controlling therotary mirror; 106, an object; 107, a lens for forming an image on CCD;108A and 108B, light wavelength separation filters for separating lighthaving wavelength from the laser light source; 109A and 109B, CCD forpicking up a monochromatic image; 109C, CCD for picking up a colorimage; 110A and 110B, signal processing parts for a monochromaticcamera; 111, a signal processing part for a color camera; 112, adistance calculation part for calculating a distance or a shape of anobject from intensity of laser light photographed by CCD 109A and 109B;and 113, a control part for adjusting synchronization of the entiredevice. Hereinafter, the description will be made of the operation of arange finder device thus configured.

[0004] The laser light sources 101A and 101B emit laser light havingslightly different wavelength. This laser light is line light having alight cross-section perpendicular to the scanning direction of a rotarymirror to be described later, and becomes line light in theperpendicular direction when a rotary mirror scans in the horizontaldirection.

[0005]FIG. 41 shows wavelength characteristics for these two lightsources. The reason why use of two light sources having close wavelengthto each other are used resides in the fact that it is caused to be lessinfluenced by dependency of the reflection factor of the object onwavelength. The laser light emitted from the laser light sources 101Aand 101B is synthesized by the half mirror 102, and is scanned on theobject 6 by the rotary mirror 104.

[0006] This scanning of the laser light is performed when the rotationcontrol part 105 drives the rotary mirror 104 at one field period. Atthat time, light intensities of both light sources is varied as shown inFIG. 42(a) within one field period. The variations in the laser lightintensity are synchronized with driving of the mirror angle, whereby theintensities of those two laser light are monitored by CCD 109A and 109Bto calculate the light intensity ratio, making it possible to measure atime at one scanning period. If the light intensity is Ia/Ib as shownin, for example, FIG. 42(b), the scanning time is measured to be t0, anda rotation angle (φ) of the rotary mirror 104 can be known from themeasured value.

[0007] The ratio of the intensities of those two laser light and themirror angle (that is, angle of the object as viewed from the lightsource side) are caused to have a one-to-one correspondence therebetweenin this manner, whereby the distance or shape of the object can becalculated from a ratio of signal levels on which light from both lightsources has been photographed in a distance calculation part to bedescribed later in accordance with the principle of triangulation.

[0008] The lens 7 [sic] forms an image of the object on CCD 109A, 109Band 109C. The light wavelength separation filter 108A transmits light inwavelength of the light source 101A, and reflects light in otherwavelength. The light wavelength separation filter 108B transmits lightin wavelength of the light source 101B, and reflects light in otherwavelength. As a result, reflected light of light of the light sources101A and 101B from the object is photographed by the CCD 109A and 109B,and light of other wavelength is photographed by the CCD 109C as a colorimage.

[0009] The light source A signal processing part 110A and light source Bsignal processing part 110B perform the similar signal processing to anordinary monochromatic camera for output from the CCD 109A and 109B. Thecolor camera signal processing part 111 performs an ordinary colorcamera signal processing for output from the CCD 109C.

[0010] The distance calculation part 112 calculates a distance for eachpixel from signal level ratio, base length and coordinate values ofpixels which have been photographed by the CCD 109A and 109B forwavelength of each light source.

[0011] FIGS. 43(a) and (b) are explanatory views for graphicallyillustrating the distance calculation. In the figures, the referencecharacter O denotes a center of the lens 107; P, a point on the object;and Q, a position of an axis of rotation of the rotary mirror. Also, forbrevity, the position of the CCD 109 is shown turned around on theobject side. Also, assuming the length of OQ (base length) to be L, anangle of P as viewed from Q in the XZ plane to be φ, an angle of P asviewed from Q to be θ, and an angle of P as viewed from O in the YZplane to be ω, the three-dimensional coordinate of P can be calculatedby the following formula (1) from the graphical relation.

Z=D tan θ tan φ/(tan θ+tan φ)  (1)

X=Z/tan θ

Y=Z/tan ω

[0012] The φ in the formula (1) is calculated by the light intensityratio of laser light sources 101A and 101B monitored by the CCD 109A and109B as described above, and θ and ω are calculated from coordinatevalues of pixels. Of the values shown in the formula (1), if all of themare calculated, the shape will be determined and if only Z isdetermined, the distance image will be determined.

[0013] On the other hand, for photography for a place where light fromthe light source cannot be directly irradiated onto an object, there hasbeen known a camera using an optical fiber. For example, as one ofendoscopes to be used at the time of examining the interior of humanbody, there are a gastrocamera and the like. In the case of thegastrocamera, the inner walls of the stomach is normally irradiated bylight irradiation from the optical fiber, reflected light from the innerwall portion is received by another optical fiber to be guided to anexternal camera part, and this is two-dimensionally processed to displaythe normal image on a monitor.

[0014] As a conventional object extraction method, the technique called“Chroma key” used in broadcasting stations is generally used.

[0015] This method is to arrange an object in front of a studio setconfigured by the background of a single color (blue) for photographing,and to judge that the blue portion is the background regarding anyportions other than it as an attention object.

[0016] In such a conventional configuration as described above, however,a modulatable light source and light source sweeping means areindispensable, and there was a problem that since mechanical operationsare included, the reliability of the device is low and the device isexpensive.

[0017] Also, although the laser element is normally modulated for use,the output and wavelength of the laser element vary depending upon thetemperature, and therefore, there is a problem that it is difficult torealize stable measurement.

[0018] Also, as in case of the conventional endoscope or the like, forphotography for a place where light from the light source cannot bedirectly irradiated onto an object, there was the problem that it isdifficult to examine whether or not there is any projecting regionbecause the image is of two-dimensional data in a camera using theoptical fiber.

DISCLOSURE OF THE INVENTION

[0019] The present invention has been achieved in the light of suchproblems, and is aimed to provide a stable range finder device free fromany mechanical operations at low cost.

[0020] It is another object of the present invention to provide a rangefinder capable of measuring a distance of an object in a place wherelight from a light source cannot be directly irradiated onto the object.

[0021] It is further another object of the present invention to providea camera which is simple in configuration and compact in size.

[0022] That is, the present invention is a range finder device, formeasuring, when a plurality of projected lights having radiationpatterns whose light intensity differs three-dimensional space-wise areirradiated onto an object from a light source on a time-sharing basis toimage-pick up reflected light of said projected light from said objectwith a camera, a distance using the light intensity of an image pickedup,

[0023] characterized in that, with respect to each of a plurality ofsurfaces including the center of said light source and the center of alens, there is obtained, in advance, relation between an angle of eachprojected light from said light source and light intensity in eachsurface,

[0024] characterized in that, at the time of actual distancemeasurement, light intensity of each pixel of said camera is measured,and on the basis of the light intensity thus measured, and relationbetween said angle and said light intensity on a predetermined surfacecorresponding to a coordinate position of said pixel measured, there isobtained said angle corresponding to said light intensity of thepredetermined pixel thus measured, and

[0025] characterized in that, on the basis of these light intensitymeasured, said angles obtained and further two-dimensional coordinateposition information on said predetermined pixel on the image, adistance to said object is calculated.

[0026] Further, the present invention is a range finder device,characterized by comprising:

[0027] a light source;

[0028] a first optical fiber for guiding light to be emitted from saidlight source;

[0029] light distribution means for dividing light guided by said firstoptical fiber into a plurality of courses;

[0030] a plurality of second optical fibers whose one end is connectedto said light distribution means, for irradiating said light dividedfrom an aperture at the other end thereof onto said object;

[0031] image pickup means for receiving reflected light of saidirradiated light to acquire image data of said object; and

[0032] distance calculation means for calculating a distance to saidobject on the basis of said image data,

[0033] characterized in that intensity of light to be irradiated ontosaid object from said other end of each of said plurality of secondoptical fibers has distribution which is different on place.

[0034] Further, the present invention is a camera for shape measuring orobject extracting, having light-emitting means for irradiating an objectwith projected light having a specified radiation pattern, for pickingup reflected light of said light-emitting means from said object toobtain a depth image using light intensity of the image picked up,characterized in that said camera has such a structure that a distancebetween said light-emitting means and an image-pickup lens is variable,and characterized in that the interval between said light-emitting meansand said image-pickup lens can be taken sufficiently large during theuse.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035]FIG. 1 is a block diagram showing the configuration of a rangefinder device according to a first embodiment of the present invention;

[0036]FIG. 2(a) is a perspective view showing the configuration of alight source in the range finder device according to the firstembodiment, and FIG. 2(b) is a plan view showing the configuration of alight source in the range finder device according to the firstembodiment;

[0037]FIG. 3 is a view showing a light pattern of a light sourceaccording to the first embodiment;

[0038]FIG. 4 is a view showing a light pattern of a light sourceaccording to the first embodiment and a light pattern in the case ofemitting a plurality of lights;

[0039]FIG. 5 is a view showing relation between a light intensity ratioaccording to the first embodiment and an angle φ from a light source;

[0040]FIG. 6 is a calculation conceptual view showing three-dimensionalpositions X, Y and Z in the first embodiment;

[0041]FIG. 7 is a block diagram showing the configuration of a rangefinder device according to a second embodiment of the present invention;

[0042]FIG. 8 is a block diagram showing distance calculation and lightintensity conversion according to the second embodiment;

[0043]FIG. 9 is a view showing a change in X-coordinate of lightintensity in the second embodiment;

[0044]FIG. 10(a) is a block diagram showing the configuration of a rangefinder device according to a third embodiment of the present invention,and FIG. 10(b) is a block diagram showing the configuration of amodification of a range finder device according to the third embodimentof the present invention;

[0045] FIGS. 11(a) to (c) are explanatory views illustrating arrangementof a lens system according to the third embodiment, and FIG. 11(d) is anexplanatory view illustrating arrangement of a transmittance changefilter according to the embodiment;

[0046]FIG. 12(a) is an explanatory view illustrating the transmittancechange filter according to the third embodiment, and FIG. 12(b) is anexplanatory view illustrating distribution of light intensity based onthe transmittance change filter according to the embodiment;

[0047] FIGS. 13(a) and (b) are outside drawings showing cameras forshape measurement and object extraction according to a fourth embodimentof the present invention;

[0048]FIG. 14 is a block diagram showing the configuration of a lightsource part of a camera according to the fourth embodiment of thepresent invention;

[0049]FIG. 15 is a view showing the principle of a light source part ofa camera according to the fourth embodiment of the present invention;

[0050]FIG. 16 is a view showing the light intensity of a light sourcepart of a camera according to the fourth embodiment of the presentinvention;

[0051]FIG. 17 is a view showing a light intensity pattern of a lightsource part of a camera according to the fourth embodiment of thepresent invention;

[0052]FIG. 18 is a view showing a light intensity pattern of a lightsource part of a camera according to the fourth embodiment of thepresent invention;

[0053]FIG. 19 is a view showing a light intensity ratio of a lightsource part of a camera according to the fourth embodiment of thepresent invention;

[0054] FIGS. 20(a) and (b) are block diagrams showing a camera accordingto the fourth embodiment of the present invention;

[0055] FIGS. 21(a) to (d) are block diagrams showing a camera (2)according to the fourth embodiment of the present invention;

[0056] FIGS. 22(a) and (b) are outside drawings showing a camera (3)according to the fourth embodiment of the present invention;

[0057] FIGS. 23(a) to (c) are block diagrams showing a camera (4)according to the fourth embodiment of the present invention;

[0058] FIGS. 24(a) to (d) are block diagrams showing a light source partof the camera (2) according to the fourth embodiment of the presentinvention;

[0059]FIG. 25 is a view showing a display method (1) of a cameraaccording to a fifth embodiment of the present invention;

[0060]FIG. 26 is a view showing a display method (2) of a cameraaccording to the fifth embodiment of the present invention;

[0061]FIG. 27 is a rear outside drawing showing a camera according tothe fifth embodiment of the present invention;

[0062]FIG. 28 is a block diagram showing a camera according to the fifthembodiment of the present invention;

[0063]FIG. 29 is a view showing an image correcting operation (1) of acamera according to the fifth embodiment of the present invention;

[0064]FIG. 30 is a view showing an image correcting operation (2) of acamera according to the fifth embodiment of the present invention;

[0065]FIG. 31 is another block diagram showing a camera according to thefourth embodiment of the present invention;

[0066]FIG. 32 is a view showing occurrence of occlusion in camerasaccording to the fourth and fifth embodiments of the present invention;

[0067]FIG. 33 is a view showing occlusion in cameras according to thefourth and fifth embodiments of the present invention;

[0068]FIG. 34 is a view showing a method of avoiding occlusion incameras according to the fourth and fifth embodiments of the presentinvention;

[0069] FIGS. 35(a) and (b) are outside drawings for avoiding occlusionin a camera (1) according to the fourth and fifth embodiments of thepresent invention;

[0070] FIGS. 36(a) and (b) are outside drawings for avoiding occlusionin a camera (2) according to the fourth and fifth embodiments of thepresent invention;

[0071] FIGS. 37(a) and (b) are outside drawings for showing an externallight source part (1) in a camera according to the fourth and fifthembodiments of the present invention;

[0072] FIGS. 38(a) and (b) are outside drawings for showing an externallight source part (2) in a camera according to the fourth and fifthembodiments of the present invention;

[0073] FIGS. 39(a) and (b) are outside drawings for showing an externallight source part (3) in a camera according to the fourth and fifthembodiments of the present invention;

[0074]FIG. 40 is a block diagram showing a conventional range finderdevice;

[0075]FIG. 41 is a characteristic diagram showing wavelengthcharacteristic of a light source for a conventional range finder device;

[0076] FIGS. 42(a) and (b) are characteristic diagrams showing intensitymodulation in a light source for a conventional range finder device; and

[0077] FIGS. 43(a) and (b) are views showing the principle ofmeasurement in a range finder.

DESCRIPTION OF THE SYMBOLS

[0078]1 Camera

[0079]1 a Infrared camera

[0080]2 a Light source

[0081]2 b Light source

[0082]3 a Infrared transmission filter

[0083]3 b Infrared transmission filter

[0084]4 a ND filter whose transmittance varies in the horizontaldirection

[0085]4 b ND filter whose transmittance varies in the horizontaldirection

[0086]5 Light source control part

[0087]6 Distance calculation part

[0088]7 Flash light source

[0089]8 Flash light source

[0090]9 Passive reflection plate

[0091]10 Passive reflection plate

[0092]11 a Field memory a

[0093]11 b Field memory b

[0094]12 a Light intensity conversion part a

[0095]12 b Light intensity conversion part b

[0096]13 Light intensity ratio calculation part

[0097]14 Distance conversion part

[0098]101A Laser light source.

[0099]101B Laser light source

[0100]102 Half mirror

[0101]103 Light source control part

[0102]104 Rotary mirror

[0103]105 Rotation control part

[0104]106 Object

[0105]107 Lens

[0106]108A Light wavelength separation filter

[0107]108B Light wavelength separation filter

[0108]109A Image pickup element

[0109]109B Image pickup element

[0110]109C Color image pickup element

[0111]110A Camera signal processing part

[0112]110B Camera signal processing part

[0113]111 Color camera signal processing part

[0114]112 Distance calculation part

[0115]113 Control part

[0116]201 Semiconductor laser

[0117]202 First optical fiber

[0118]203 Light distributor

[0119]204 Collimator lens

[0120]206 Camera part

[0121]207 Second optical fiber

[0122]501 Housing

[0123]502 Housing 503 Lens

[0124]504 Recording media

[0125]505 First strobe

[0126]506 Second strobe

[0127]507 Finder

[0128]508 Strobe part

[0129]509 Camera body housing

[0130]510 Joint part

[0131]511 Camera body

[0132]512 Light source part housing

[0133]513 Light source part housing

[0134]514 Third strobe

[0135]515 Fourth strobe

[0136]516 Joint part

[0137]517 Light source part

[0138]518 Display panel

[0139]519 Touch panel

[0140]520 Object (foreground)

[0141]521 Object (background)

[0142]527 Portion judged to be the foreground by malfunction

[0143]528 Shading plate

[0144]529 Strobe light-emitting tube A

[0145]530 Strobe light-emitting tube B

[0146]531 Liquid crystal barrier

[0147]532 Display part

[0148]533 Image pickup part

[0149]534 Light control part

[0150]535 Distance calculation part

[0151]536 Color image calculation part

[0152]537 Control part

[0153]538 Media recording and reproducing part

[0154]539 Analysis part

[0155]540 Object (foreground)

[0156]541 Object (background)

[0157]542 Portion for which light from the light source part isintercepted

[0158]543 Light source part 3

[0159]544 Light source part 4

[0160]545 Camera mounting screws

[0161]546 Light source part housing (1)

[0162]547 Light source part housing (2)

[0163]548 Light source part fixing base

[0164]549 Light source part fixture (strobe shoe fitting)

[0165]550 Image memory

[0166]551 Passive reflection plate (1)

[0167]552 Passive reflection plate (2)

[0168]5100 Portion which has been judged to be the background

BEST MODE FOR CARRYING OUT THE INVENTION

[0169] Hereinafter, with reference to the drawings, the description willbe made of a range finder device according to embodiments of to thepresent invention.

[0170] (First Embodiment)

[0171]FIG. 1 is a block diagram showing a range finder according to afirst embodiment of the present invention. In FIG. 1, the referencenumeral 1 denotes a camera; 2 a and 2 b, light sources; 5, a lightsource control part; and 6, a distance calculation part. Hereinafter,the description will be made of an operation of the above-describedconfiguration.

[0172] The light source control part 5 causes the light sources 2 a and2 b to alternately emit light for each field period in synchronism witha vertical synchronizing signal of the camera 1. As the light sources 2a and 2 b, there can be used those in which flash light sources 7 and 8such as xenon flash lamps are lengthwise arranged and the directions ofpassive reflection plates behind them are laterally deviated as shownin, for example, FIG. 2(a). FIG. 2(b) is a plan view of FIG. 2(a). Thelight sources 2 a and 2 b radiate light within ranges A and Brespectively. This xenon lamp has a small-sized light emitting portion,and one which can be regarded as a point light source as viewed fromabove is preferable. Further, the light sources 2 a and 27 b [sic] arelengthwise arranged, the distance therebetween is about 1 cm, and theselight sources look as if light was emitted substantially from one point.

[0173] A light pattern to be radiated from such light sources becomes asshown in FIG. 3. This indicates, when light is projected onto aprovisional screen, a size of brightness of the screen surface by adirection ->in the figure. That is, the respective light sources havecharacteristic properties that the screen surface is brightest at thecentral axis, and becomes darker toward the marginal portion. It isbright at the center and dark in the marginal portion in this mannerbecause semi-cylindrical passive reflection plates 9 and 10 are locatedbehind the flash light sources 7 and 8. Also, the directions of thosesemi-cylindrical passive reflection plates 9 and 10 are deviated, andthe respective projected light is emitted so that it is partlyoverlapped.

[0174]FIG. 4 shows relation between angles of projected light from thelight sources and light intensity in a plane of H direction of FIG. 3.This H direction is a direction of a crossing line between an arbitraryplane S, of a plurality of planes including the center of the lightsource and the lens center, and the above-described provisional screen.In α portion of these light patterns, light to be irradiated from twolight sources into the object space becomes bright on the right side inone and bright on the left side in the other as viewed from each lightsource. This pattern varies, however, also in the height-wise direction(Y direction).

[0175]FIG. 5 indicates the relation between the light intensity ratio inthe object illumination by the two projected lights and an angle φ, madeby the X-axis, of the one obtained by projecting the projected lightonto the XZ plane in the α portion in FIG. 4. In the α portion, therelation between the light intensity ratio and angle φ is a one-to-onecorrespondence. In order to measure a distance, two types of lightpatterns are alternately projected onto a plane, which is spaced apartby a predetermined distance from the light sources and is set upvertically, and such data on the relation between light intensity ratioand angle of projected light as shown in FIG. 5 is obtained in advancefor each Y-coordinate (which corresponds to Y-coordinate on CCD) fromthe result obtained by image-picking up this reflected light with thecamera 1. The “for each Y-coordinate” means for each of a plurality ofplanes including the light source center and the lens center.

[0176] Also, if the light sources are located such that a segmentbetween the lens center of the camera 1 and the light sources runsparallel to the X-axis of the CCD image pickup surface, distancecalculation can be accurately performed through the use of data on therelation between the light intensity ratio determined for eachY-coordinate and the angle of projected light. Hereinafter, thedescription will be made of a distance calculation method using thelight intensity ratio.

[0177] When a point P in FIG. 1 is set to an attention point, an angle φof the point P as viewed from the light sources is measured through theuse of a luminance ratio obtained from image pickup data when two typesof light patterns are irradiated concerning the point P in an imagepicked up by the camera 1, and the relation of FIG. 5 corresponding to aY-coordinate value of the point P. In this respect, an assumption ismade that the relation of FIG. 5 has the characteristic properties thatvary depending upon the Y-coordinate value as described above, and thatthe relation between the light intensity ratio and an angle φ from thelight sources in the horizontal direction has been prepared bypreliminary measurement for each Y-coordinate. Also, an angle θ withrespect to the point P as viewed from the camera is determined by theposition (that is, pixel coordinate value of the point P) in the image,and a camera parameter (focal length, optical center position of thelens system). Thus, the distance is calculated from the two angles and adistance (base length) between the light source position and the opticalcenter position of the camera in accordance with the principle oftriangulation.

[0178] Assuming the optical center of the camera to be the origin,setting the optical axis direction of the camera as Z-axis, thehorizontal direction as X-axis, and the perpendicular direction asY-axis, and assuming an angle, made by the X-axis, of the direction ofthe attention point as viewed from the light source to be φ, an angle,made by the X-axis, of the direction of the attention point as viewedfrom the camera to be θ, and the light source position to be (0, −D),that is, the base length to be D, the depth value Z of the attentionpoint P can be calculated from the above-described formula (1)

Z=D tan θ tan φ/(tan θ−tan φ)

[0179] According to the present embodiment as described above, adistance is measured by correcting any variations in light intensitygenerated by light sources or the optical system at the time ofmeasuring the distance by means of a range finder using light intensity,whereby it is possible to realize a stable range finder device with highprecision capable of implementing all by electronic operations.

[0180] In this respect, at the front of an infrared camera having arange finder according to the present embodiment, a half mirror or adichroic mirror and a color camera are arranged, whereby a color imagehaving the same viewpoint as well as the distance, image can beobtained, and this technique is included in the present invention.

[0181] In this respect, in the distance calculation part according tothe present embodiment, the description has been made of the case whereonly the distance Z is calculated to output the calculation result as adistance image, but it may be possible to output three-dimensionalcoordinate data by calculating all three-dimensional coordinate valuesX, Y and Z from formulas (1) and (2) using an angle ω shown in FIG. 6,and this technique is included in the present invention.

X=Z/tan θ

Y=Z/tan ω  (2)

[0182] In this respect, in the present embodiment, if light sources 2 aand 2 b are caused to emit light at the same time, and are used as anormal flash lamp in which brightness in one center is great and themarginal portion becomes dark as indicated by a dotted line in FIG. 4, anormal two-dimensional image can be image-picked up.

[0183] Also, in the present embodiment, if an infrared passing filter isinserted at the front of the light source 2 and a filter havingsensitivity in an infrared wavelength area is used for the camera 1, itis made possible to prevent lighting of a flashlight from hindering theuser or an image pickup picture by the user or the other camera. Also,if an image is image-picked up coaxially with the infrared camera and byan ordinary color camera using a half mirror, a dichroic mirror and thelike, a depth image and a texture image corresponding thereto can alsobe image-picked up at the same time.

[0184] Also, in the present embodiment, since the flashlight flashes forhundreds microsecond, if the camera 1 is set so as to be exposed bymeans of a shutter operation only during such period, it will bepossible to suppress the background light from affecting the distancemeasurement and to image-picked up a distance image even in a placewhich is bright to some degree.

[0185] Also, in the present embodiment, two types of light patterns areirradiated onto an object, and the light intensity ratio for each pixelhas been calculated using image pickup pictures in the respective cases.It may be possible, however, to also image-pick up an image when nolight pattern is irradiated and obtain three types (two types of lightpatterns and one type of no light pattern) of images in total forcalculation. In this case, at the time of calculating the lightintensity ratio for each pixel, a differential value obtained bysubtracting light intensity in the absence of any light pattern from therespective light intensity values during light pattern irradiation willbe calculated. Then, a ratio of these differential values will becalculated to make it into the light intensity ratio. Thus, in the caseof image pickup in a bright place, it is possible to suppress distancecalculation error based on background light.

[0186] (Second Embodiment)

[0187]FIG. 7 is a block diagram showing a range finder device accordingto a first embodiment of the present invention. In FIG. 7, the referencenumeral 1 a denotes a camera having sensitivity in infrared light; 2 aand 2 b, light sources; 3 a and 3 b, infrared transmission filters; 4 aand 4 b, ND filters whose transmittance varies in the horizontaldirection; 5, a light source control part; and 6, a distance calculationpart. Hereinafter, the description will be made of an operation of theabove-described configuration.

[0188] The light source control part 5 causes the light sources 2 a and2 b to emit light for each field period in synchronism with a verticalsynchronizing signal of the infrared camera 1 a. As the light sources 2a and 2 b, a light source such as a xenon lamp, which flashes, having asmall-sized light emitting portion, (which can be regarded as a pointlight source), is preferable. Also, the light sources 2 a and 2 b arearranged in the vertical direction.

[0189] At the front of each light source, there are arranged infraredtransmission filters 3 a and 3 b, and ND filters 4 a and 4 b. Thetransmittance of the ND filter 4 a, 4 b varies in the horizontaldirection. FIG. 2 shows a relation between an angle from the lightsource in the horizontal direction and the transmittance of the NDfilters 4 a and 4 b.

[0190] Because of these ND filters, light to be irradiated in objectspace from two light sources becomes bright on the right side in one andbright on the left side in the other as viewed from the light sources.As a result, light which is bright on the right side or on the left sideas described above is alternately projected onto the object for eachfield period.

[0191]FIG. 5 indicates a relation between the light intensity ratio ofthe two projected lights and an angle from the light sources in thehorizontal direction. Hereinafter, the description will be made of adistance calculation method using the light intensity ratio.

[0192] When a point P in FIG. 7 is set to an attention point, an angleof the point P as viewed from the light source is measured from aluminance ratio between fields concerning the point P in an imageimage-picked up by the camera 1 a through the use of the relation ofFIG. 5. Also, an angle with respect to the point P as viewed from thecamera is determined from the position (that is, pixel coordinate valueof the point P) in the image, and a camera parameter (focal length,optical center position of the lens system). Thus, the distance iscalculated from the two angles and a distance (base length) between thelight source position and the optical center position of the camera inaccordance with the principle of triangulation.

[0193] Assuming the optical center of the camera to be the origin,setting the optical axis direction of the camera as Z-axis, thehorizontal direction as X-axis and the vertical direction as Y-axis, andassuming an angle, made by the X-axis, of the direction of the attentionpoint as viewed from the light source to be φ, an angle, made by theX-axis, of the direction of the attention point as viewed from thecamera to be θ, and the light source position to be (0, −D), that is,the base length to be D, the depth value Z of the attention point P canbe calculated as the following formula:

Z=D tan θ tan φ/(tan θ−tan φ)

[0194] The distance calculation part 6 calculates a distance image froma video signal of the camera 1 a. The calculation method may be the sameas in the: first embodiment, and there is another method capable ofperforming more accurate measurement as described below. FIG. 8 is ablock diagram showing the distance calculation part 6. In FIG. 8, thereference numerals 711 [sic] and 11 b denote field memories; 12 a and 12b, light intensity correction means; 13, light intensity ratiocalculation means; and 14, distance conversion means. Hereinafter, thedescription will be made of the operation of each component.

[0195] An image image-picked up by the camera 1 a is written in thefield memories 11 a and 11 b by each field.

[0196] The light intensity correction means 12 a and 12 b is means forcorrecting the light intensity written in the field memories. The reasonfor the correction will be described below. FIG. 9 shows a relationbetween the light intensity to be image-picked up and the pixelcoordinate value when light is irradiated (in a state free from any NDfilter) on a screen having a fixed distance Z from a point light sourceto image-pick up light reflected by the surface. FIG. 9one-dimensionally shows only in the horizontal direction for brevity,but the light intensity likewise shows curvilinear distribution also inthe vertical direction.

[0197] As causes for this distribution, there are conceived peripheralextinction based on the lens system of the camera, variations inintensity of reflected light caused by variations in the angle ofincidence of a ray of light with respect to the object surface, andvariations in light intensity due to an angle from the light sourcesamong others. Since the variations in light intensity caused by thesecauses become errors at the time of observing the light intensity ratio,that is, errors during distance measurement, it becomes necessary toconvert the light intensity in order to improve the distance measurementaccuracy. The presence of these errors may cause any portion other thana monotonous increasing curve in the characteristic curve of FIG. 5. Insuch a portion, the light intensity and the angle do not have aone-to-one correspondence therebetween, and as a result, the measurementresult is disturbed. Also, if there were not these errors, there wouldbe advantages that the light intensity (ratio) in the Y-axis directionbecomes constant, and that one conversion table of FIG. 5 is required(in the first embodiment, a conversion table for the number forY-coordinate value is required).

[0198] In order to reduce the measurement errors in the light intensityconversion means 12 a and 12 b, two-dimensional curve distribution inlight intensity in an image on a screen spaced apart by a referencedistance in the absence of the ND filter is measured in advance, and atthe time of obtaining relation (corresponding to FIG. 5) between thelight intensity and the angle of the projected light, and at the time ofmeasuring an actual distance of the object, the light intensity of thefield memory is corrected and converted in accordance with the curvedistribution in light intensity measured in advance. A factor (that is,ratio of light intensity picked up in each pixel corresponding to a peakvalue or an arbitrary value) for correcting the curve distribution oflight intensity to a fixed value is held as a two-dimensional LUT(look-up table), and the correction and conversion are performed bymultiplying the data in the field memory by a correction factor for eachpixel.

[0199] The reference distance is, if a distance in arranging the objectis known in advance, set to a value close to the distance, to therebymake it possible to improve the accuracy at the time of measuring thedistance.

[0200] According to the present embodiment as described above, adistance is measured by correcting any errors in light intensity causedby a light source or an optical system at the time of measuring thedistance by means of a range finder using light intensity., whereby itis possible to realize a stable range finder device with high precisioncapable of implementing all by electronic operations.

[0201] In this respect, at the front of an infrared camera having arange finder according to the present embodiment, a half mirror or adichroic mirror and a color camera are arranged, whereby a color imagehaving the same point of view as well as the distance image can beobtained.

[0202] In this respect, in the distance calculation part according tothe present embodiment, the description has been made of the example inwhich only the distance Z is calculated and the calculation result isoutputted as the distance image, but it is possible to calculate allthree-dimensional coordinate values X, Y and Z using the angle ω shownin FIG. 6 from the following formulas:

Z=D tan θ tan φ/(tan θ−tan φ)

X=Z/tan θ

Y=Z/tan ω

[0203] and to output the three-dimensional coordinate data.

[0204] In this respect, in the light intensity correction in thedistance calculation part according to the present embodiment, in thecase where the object is spaced apart from the reference distance, theposition of pixels to be image-picked up is shifted (that is, a parallaxoccurs) and therefore, the distance measurement precision isdeteriorated. In such a case, a plurality of light intensity correctionamounts for reference distances are prepared in advance, correction fora certain reference distance is first performed to calculate thedistance, and subsequently, the distance is calculated again by using acorrection amount for a reference distance close to the previous case tothereby make it possible to improve the measurement precision.

[0205] In this respect, in the present embodiment, if light sources 2 aand 2 b are caused to emit light at the same time, and are used as anormal flash lamp in which brightness in one center is great and themarginal portion becomes dark as indicated by dotted line in FIG. 4, anormal two-dimensional image can be picked up.

[0206] Also, in the present embodiment, if an image is picked upcoaxially with the infrared camera and by an ordinary color camera usinga half mirror, a dichroic mirror and the like, a depth image and atexture image corresponding thereto can also be picked up at the sametime.

[0207] Also, in the present embodiment, since the flashlight flashes forhundreds microsecond, if it is set such that the camera 1 is exposed bymeans of a shutter operation only during the period of time, it will bepossible to suppress the background light from affecting the distancemeasurement and to pick up a distance image even in a place which isbright to some degree.

[0208] Also, in the present embodiment, two types of light patterns areirradiated onto an object, and the light intensity ratio for each pixelhas been calculated using image pickup pictures in the respective cases.It may be possible, however, to also pick up an image when no lightpattern is irradiated and to obtain three types (two types of lightpatterns and one type of no light pattern) of images in total forcalculation.

[0209] In this case, at the time of calculating the light intensityratio for each pixel, a differential value obtained by subtracting lightintensity without light pattern from the respective light intensityvalues during light pattern irradiation will be calculated. Then, aratio of these differential values will be calculated to make it intothe light intensity ratio. Thus, in the case of image-picking up in abright place, it is possible to suppress any distance calculation errorbased on background light.

[0210] Also, for the light pattern to be projected onto an object in thepresent embodiment, it may be possible to use a light transmission typeliquid crystal display device (such device as used in an ordinary liquidcrystal video projector) and one light source in place of the ND filters4 a and 4 b whose transmittance varies in the horizontal direction andthe light sources 2 a and 2 b. These ND filters and two light sourcesare switched to a light transmission pattern of the light transmissiontype liquid crystal display device to cause the light source to emitlight twice, or the light source is left lighted to switch to two typesof light patterns of the light transmission type liquid crystal displaydevice, whereby it is possible to irradiate two types of light patternsonto the object on a time-sharing basis as in the case of the presentembodiment.

[0211] (Third Embodiment)

[0212]FIG. 10(a) is a schematic perspective view showing a thirdembodiment of a range finder according to the present invention. Withreference to the figure, the description will be made of theconfiguration of the present embodiment hereinafter.

[0213] As shown in FIG. 10(a), a semiconductor laser 201 is light sourcemeans for emitting light with a wavelength λ. A first optical fiber 202is means for guiding light to be emitted from the semiconductor laser201 to a light distributor 203. Also, a collimator lens 204 is arrangedbetween the first optical fiber 202 and the semiconductor laser 201. Thelight distributor 203 is light distribution means for dividing the lightguided through the first optical fiber 202 into two courses. Also, thelight distributor 203 has a shutter mechanism, and is means fortransmitting the light divided to second optical fibers a and b on atime-sharing base. The second optical fiber a (205 a) and the secondoptical fiber b (205 b) are optical fibers connected, at one endthereof, to the light distributor 203 respectively, for irradiating thelight divided from an aperture at the other end onto an object (forexample, the inner walls of the stomach, or the like). A camera part 206is image pickup means for acquiring image data of the object receivedthrough light-receiving optical fiber bundle 207 by means of reflectedlight from the object. In this respect, at the tip end of thelight-receiving optical fiber bundle 207, there is arranged a lens 210in proximity thereto. CCD 209 is an image pickup element mounted to thecamera part 206 so as to receive light from the light-receiving opticalfiber bundle 207. Light to be irradiated from the aperture 208 a of thesecond optical fiber a (205 a) shows such light intensity distributionas shown in FIG. 4 which has been described in the embodiment. Light tobe irradiated from the aperture 208 b of the second optical fiber b (205b) is also the same. These lights has different light intensitydistribution depending upon the position in the horizontal directionbecause light to be emitted from the aperture of the optical fiberdiffuses based on the angular aperture. Therefore, by adjusting theangular aperture, the shape of the light intensity distribution can bechanged. In this respect, this angular aperture can be adjusted to somedegree by setting the refractive index of the optical fiber in thediameter-wise direction to a predetermined value.

[0214] In this respect, a range finder according to the presentembodiment has distance calculation means (not shown) provided with thesame function as the distance calculation part 6 described in theembodiment, for calculating a distance up to the object on the basis ofimage data from the camera part 206. Also, for both the first opticalfiber 202 and the second optical fibers a and b (205 a and 205 b), oreither of them, optical fiber bundle may be used as a matter of course.

[0215] With the above-described configuration, the operation of thepresent embodiment will be described with reference to FIG. 10(a).

[0216] A range finder according to the present embodiment can beutilized as an endoscope such as a gastrocamera.

[0217] More specifically, the tip ends of the second optical fibers aand b (205 a and 205 b) and the tip end of the light-receiving opticalfiber 207 are inserted into the stomach of a patient.

[0218] From the apertures of the second optical fibers a and b, lighthaving such light intensity distribution characteristic as shown in FIG.4 is irradiated on the time-sharing basis as in the case of the firstembodiment. The light-receiving optical fiber 207 receives lightreflected by these light. Further, the camera part 206 transmits theimage data on the inner walls of the stomach obtained from these lightreflected to the distance calculation part. The distance calculationpart calculates, as in the case of the first embodiment, thethree-dimensional distance data on the inner walls of the stomach foroutputting. The distance data outputted is transmitted to a monitor (notshown) to be three-dimensionally displayed. A doctor can, while viewingthe monitor, view the image of the diseased portion which hasthree-dimensionally been displayed by moving the tip end of the secondoptical fiber. Thus, the doctor can more accurately examine than before.

[0219] In this respect, in the above-described embodiment, thedescription has been made of a range finder configured by onesemiconductor laser as the light source part, but the present inventionis not limited thereto, and a range finder configured by two lightsource parts as shown in, for example, FIG. 10(b) may be used. Morespecifically, in this case, semiconductor lasers 201 a and 201 b as thelight source part are provided with optical fibers 205 a and 205 b forindividually guiding those lights emitted on the object side toirradiate the object. Also, a collimator lens 204 a, 204 b is arrangedbetween each optical fiber 205 a, 205 b and each semiconductor laser 201a, 201 b. Such a configuration exhibits the same effect as describedabove.

[0220] Also, in the above-described embodiment, the description has beenmade of the configuration in which there is provided a light distributor203 between the first optical fiber 202 and two second fibers 205 a and205 b, but the present invention is not limited thereto, and it may bepossible to construct, in place of, for example, the light distributor203 and the second optical fibers 205 a and 205 b, such that lightguided from the first optical fiber is divided into two courses at thetip end portion of the fiber and there is provided light branch means(not shown) for irradiating the object. In this case, the second opticalfiber can be omitted, and yet the same effect as described above isexhibited.

[0221] Also, in the above-described embodiment, the description has beenmade of the configuration in which nothing has been provided in front ofthe optical fibers 205 a and 205 b as shown in FIG. 11(a), but thepresent invention is not limited thereto, and it may be possible toconstruct such that a collimator lens 301 (See FIG. 11(b).) is arrangedat the front of the aperture 208 a, 208 b of each optical fiber 205 a,205 b, or that a cylindrical lens (or a rod lens) 302 (See FIG. 11(c).)is arranged at the front of each aperture 208 a, 208 b. This enables theintensity of light to be irradiated from the aperture to beposition-wise uniformly varied more effectively. In this respect, it isalso possible to output light, which has no different light intensitylocally, from the front of each aperture 208 a, 208 b, and instead, toarrange a transmittance change filter 1 (303 a) and a transmittancechange filter 2 (303 b), whose light transmittance differsposition-wise, at the front of each aperture 208 a, 208 b.

[0222] With reference to FIGS. 12(a) and (b), the description will befurther made of the characteristic properties of the filter shown inFIG. 11(d).

[0223] The intensity distribution of light, which passed through thetransmittance change filter 1 (303 a) shown in, for example, FIG. 12(a),is set such that it becomes the one denoted by the reference numeral 401a in FIG. 12(b). In contrast, the intensity distribution of light, whichpassed through the transmittance change filter 2 (303 b), is set suchthat it becomes the one denoted by the reference numeral 401 b in thefigure. FIG. 12(b) is a view representing the light intensitydistribution for a range a shown in FIG. 4. The present invention can beimplemented even if such transmittance change filter is used.

[0224] Also, in the above-described embodiment, the description has beenmade of the case where the light distributor has been provided with ashutter mechanism in such a manner that the object is irradiated withlight on a time-sharing basis, but the present invention is not limitedthereto, and for example, light from the light source includes lighthaving a plurality of frequencies, and the light distributor is providedwith a filter, whereby light having different wavelength is irradiatedfrom the aperture. Thus, the camera part is provided with a filter and alight-receiving element, which are capable of distinguishing these twotypes of wavelength for receiving, to thereby make it possible toirradiate the object with each light having two types of wavelength atthe same time. This enables the measuring time to be shortened. Even inthe configuration shown in FIG. 10(b), if the wavelength of thesemiconductor lasers 201 a and 201 b are made different from each other,and the camera part 206 is provided with a filter and a light-receivingelement, which are capable of distinguishing these two types ofwavelength for receiving, it becomes possible to shorten the measurementtime in the same manner as described above.

[0225] Also, in the above-described embodiment, a semiconductor laserhas been used as the light source, but the present invention is notlimited thereto, and for example, LED, a lamp or the like may be used.

[0226] Next, the description will be made of a camera according to thepresent invention, which is obtained by implementing such a contrivanceas to make the above-described range finder device according to thepresent invention more compact and simple in configuration.

[0227] More specifically, in the above-described range finder device,the light passive reflection plates have been disposed in deviatedrelationship with each other with respect to the light sources 2 a and 2b as shown in FIG. 2, it is necessary to mount light filters whose lighttransmittance differs depending upon the horizontal place in front ofthe light-emitting tube, and it can be said that the configuration iscomplicated.

[0228] Also, unless the camera lens and the light source are spaced morethan several tens centimeters apart from each other, the measurementaccuracy will not be possible because the triangulation is used, and thecamera would be considerably large even if an attempt is made to housethem within the camera housing.

[0229] Also, there was a defect that it is impossible to simplycalculate to measure the sizes or dimensions of an object image-pickedup with a conventionally-known camera unless the distance up to theobject is known. Also, it was impossible to know the sizes of the objectfrom a color image once picked up.

[0230] Also, when an attempt is made to extract an object from an imagepicked up with a conventionally-known camera, an environment having abackground of a single color must be prepared in advance, andlarge-scale preparation was required.

[0231] Hereinafter, with reference to the drawings, the description willbe made of a shape measuring camera and an object extracting cameracapable of solving those inconveniences and the like, according to anembodiment of the present invention.

[0232] (Fourth Embodiment)

[0233]FIG. 1(a) [sic] is a block diagram showing a shape measuringcamera and an object extracting camera according to a fourth embodimentof the present invention. Also, FIG. 20 is a block diagram showing thiscamera.

[0234] In FIG. 13, the reference numerals 501 and 502 denote a camerahousing; 503, a photographing lens; 504, recording media; 505 and 506,first and second strobes, each forming the light source partrespectively; and 507, a finder.

[0235] In FIG. 20, the reference numeral 532 denotes a display part;533, an image pick up part; 534, alight source control part; 535, adistance calculation part; 536, a color image calculation part; 538, amedia recording/reproducing part; and 550, an image memory.

[0236] This shape measuring camera is configured such that a housing 501containing the camera part and a housing 502 containing a light-emittingpart have different thickness from each other and can be fitted intoeach other in an overlapped manner as shown in FIG. 13(a), and furtherthat the state of FIG. 13(a) or the state of FIG. 13(b) can be selectedby sliding the housings 501 and 502 by the user. During carrying, thesmall-sized state is kept in the state of FIG. 13(a), while duringimage-picking up, the housing is extended into such a state as shown inFIG. 13(b) for use. This enables an interval D between the center of thelens 503 and the strobe 505, 506 in the light source part to be setlarge during the use. FIG. 20(a) shows a simple type using no imagememory 550, and FIG. 20(b) shows a type having an image memory, capableof image-picking up and displaying at high speed.

[0237] The strobe 505, 506 in the light source part is constructed asshown in, for example, FIG. 2, and is configured by a strobelight-emitting tube 530 and a shading plate 528 having a hole with theposition of its center shifted. Light emitted from the segment of alight-emitting tube 530 is emitted while the way of intercepted light isvarying depending upon the position by a shading plate 528 as shown inthe plan view of FIG. 15. At this time, the position of the hole in theshading plate 528 is deviated from the strobe light-emitting tube 530,and such light as to become increasingly intenser from point A towardpoint B on a straight line 1 is generated. This generates such a lightpattern that the light intensity varies in the opposite directions toeach other from two strobe light-emitting tubes as shown in FIG. 16.Next, the description will be made of a method for calculating a depthdistance using such light. In this respect, its contents are almost thesame as the calculation method for depth distance already described.

[0238] A light pattern thus obtained is a pattern in which the lightintensity varies as shown in FIG. 17. FIG. 18 one-dimensionally showsthese variations in the light intensity in the horizontal X-direction.In α portion of this light pattern, light to be irradiated from twolight sources into the object space

[0239] becomes bright on the right side in one and bright on the leftside in the other as viewed from each light source. This pattern varies,however, also in the height-wise direction (Y direction).

[0240]FIG. 19 shows the relation between the light intensity ratio andan angle φ from the light source in the horizontal direction in theobject illumination by the above-described two projected light in the αportion of FIG. 18. In the α portion, the relation between the lightintensity ratio and the angle φ from the light source in the horizontaldirection is a one-to-one correspondence therebetween. In order tomeasure a distance, it is necessary to alternately project two types oflight patterns onto a plane which has been set up vertically in advance,and to obtain in advance such data on the relation between lightintensity ratio and position from the light source in the horizontaldirection as shown in FIG. 17 for each Y-coordinate from the resultobtained by image-picking up this reflected light with the camera 501.

[0241] Also, if the light sources are located such that a segmentbetween the lens center of the camera 501 and the light source runshorizontal to the X-axis of the image pickup surface, the distance canbe accurately calculated through the use of data on the relation betweena light intensity ratio determined for each Y-coordinate and positionsfrom the light sources in the horizontal direction. This is calculatedby the distance calculation part of FIG. 20(a). Hereinafter, thedescription will be made of a distance calculation method using thelight intensity ratio.

[0242] In the case where a point P in FIG. 20(a) is set to an attentionpoint, when two types of light patterns from respective strobes 505 and506 in the light source concerning the point P on an image picked up bythe image pickup part 533 on the basis of the user's image-picking upintention are projected by the light source control part 534 on atime-sharing basis, an angle φ of the point P as viewed from the lightsource is measured through the use of a luminance ratio obtained fromthe image pickup data, which is the output from the image pickup part533, and the relation of FIG. 19 corresponding to the Y-coordinate valueof the point P.

[0243] In this respect, the assumption is made that the relation of FIG.19 has characteristic properties that differ depending upon theY-coordinate value as described above, and that the relation between thelight intensity ratio and the angle φ from the light source in thehorizontal direction has been prepared for each Y-coordinate bymeasurement in advance. Also, an angle θ with respect to the point P asviewed from the camera is determined from the position (that is, pixelcoordinate value of point P) in the image, and a camera parameter (focallength, optical center position of lens system). Thus, the distance iscalculated from the above-described two angles and the distance (baselength D) between the light source position and the optical centerposition of the camera in accordance with the principle oftriangulation.

[0244] Assuming the optical center of the camera to be the origin,setting the optical axis direction of the camera as Z-axis, thehorizontal direction as X-axis, the vertical direction as Y-axis, andassuming an angle, made by the X-axis, of the direction of the attentionpoint as viewed from the light source to be φ, an angle, made by theX-axis, of the direction of the attention point as viewed from thecamera to be θ, and the light source position to be (0, −D), that is,the base length to be D, the depth value Z of the attention point P canbe calculated as the following formula:

Z=D tan θ tan φ/(tan θ−tan φ)

[0245] When the value of D (distance between lens and light source part)is small at this time, accuracy of the depth value Z measured isdegraded. If the D value is set to 20 to 30 cm for an object up to adistance of, for example, about 3 m, the depth can be measured with anerror of plus or minus about 1% of the measured distance. As the D valuebecomes smaller than 20 to 30 cm, the measurement error furtherincreases. Also, the X and Y coordinates of the attention point P aregiven by the following formulas:

X=Z/tan θ

Y=Z/tan ω

[0246] Also, a color image calculation part 536 calculates an imageobtained by adding and averaging image pickup data when theabove-described two types of light patterns are irradiated to make itinto a color image. These two types of light patterns havecharacteristic properties that the brightness varies complementally toeach other as shown in FIG. 18, and by adding and averaging them, thesame color image as a color image obtained by picking up with strobeswith uniform brightness can be obtained.

[0247] The color image and depth image which have been thus obtained aredisplayed on a display part 532, and are recorded in recording media 504through a media recording/reproducing part 538. Of course, the colorimage and depth image which have been once recorded can also be read outby the media recording/reproducing part 538 to be displayed on thedisplay part 532.

[0248] If the image data from the image pickup part 533 is onceaccumulated in an image memory 550 as shown in FIG. 20(b), the image canbe continuously inputted. Also, a plurality of images recorded on therecording media 504 once also can be read out on the image memory 550 tobe reproduced and displayed at high speed.

[0249] According to the present embodiment as described above, it ispossible to generate a plurality of light patterns in a singleconfiguration, and to realize a shape measuring camera with stableconfiguration only through the use of a straight-line shaped strobelight-emitting tube and a shading plate with a hole for a lightintensity change pattern.

[0250] Also, it is possible to realize a shape measuring camera capableof taking the interval D large between the lens 503 and the strobes 505and 506 in the light source part by making it small-sized duringcarrying and by extending the main body during image-picking up, andcapable of measuring a depth image with high accuracy.

[0251] (Fifth Embodiment)

[0252]FIG. 28 is a block diagram showing a shape measuring camera and anobject extracting camera according to a fifth embodiment of the presentinvention. In FIG. 28, the reference numerals 501 and 502 denote acamera housing; 505 and 506, first and second strobes, each forming thelight source part respectively; 518, a display panel; 519, a touchpanel; 532, a display part; 533, an image pickup part; 535, a distancecalculation part; 536, a color image calculation part; 538, a mediarecording/reproducing part; and 537, a control part. Hereinafter, thedescription will be made of the operation of the shape measuring cameraand the object extracting camera having the above-describedconfiguration.

[0253]FIG. 27 shows the back of the shape measuring camera. On the back,the display panel 518 and the touch panel 519 are piled up in a sameposition to display a color image or a depth image which has been pickedup, and are configured such that the user can denote the attentionposition (coordinate) in the image using the finger or a rod-shapedobject.

[0254]FIG. 28 is a block diagram showing display and distancemeasurement. A distance image and a color image which have been pickedup are inputted into the control part 537, and user's attention positiondesignating coordinates are also inputted into the control part 537. Thecontrol part 537 displays a color image picked up on the display panel518 and calculates an actual distance and the like from a plurality ofattention designating coordinates inputted by the touch panel 519 and adepth image to display on the display panel 518.

[0255]FIG. 25 shows an aspect of attention position designation. First,it is assumed that a color image for a desk picked up by the user isdisplayed on the display part 518. The user denotes designating pointsA523 and B524 using the finger or a rod-like object.

[0256] When they are denoted, the shape measuring camera calculates thedistance Lab of a segment AB between points A and B, that is,

Lab={square root}{square root over ({(Xa−Xb)²+(Ya−Yb)²+(Za−Zb)²})}

[0257] using the values of actual coordinates A (Xa, Ya, Za) and B (Xb,Yb, Zb) of respective coordinate positions of the depth image obtainedto display in another portion on the display panel 518. In this example,it is displayed that the length of AB is 25 cm. In this manner, the usercan measure a distance between points, which should be measured, of theobject image-picked up without touching it even if it is a length in thedepth-wise direction.

[0258] Also, the size of a circular object and not a straightline-shaped object can be measured in the similar manner. FIG. 26 showsthe case where a circular table has been image-picked up. For example,while viewing a color image which has been image-picked up and displayedon the display panel 518, the user denotes three points, A523, B524 andC526 of an adequate position of a circumferential portion of a circle tobe measured by touching them on the touch panel using the finger or arod-shaped object.

[0259] Thereafter, the shape measuring camera determines, from spacecoordinate values A (Xa, Ya, Za), B (Xb, Yb, Zb) and C (Xc, Yc, Zc) forthese three points, a formula for a circle which passes these points.Although there are various methods for determining it, for example,perpendicular bisectors for segments AB and BC are determined and theirpoint of intersection is assumed to be the center G (Xg, Yg, Zg) of thecircle. Next, a mean value of the length of segments GA, GB and GC canbe made into the radius of the circle.

[0260] The radius thus obtained is displayed to be 50 cm in FIG. 26, ofwhich the user is notified. By doing so, the size of such a complicatedshape as a circle can also be measured without touching the object. Inaddition, for any shape having a mathematical expression for definingthe shape such as an equilateral triangle and an ellipse, its size canbe measured from the depth image without touching the object bydesignating a plurality of points by the user. Also, in this case, theuser has inputted the coordinates for the attention point using thetouch panel, but it may be possible to display a cursor (such as afigure of cross), which moves left, right, up or down, on the displaypanel 518, and to denote by moving its position with a push-button forinputting the coordinates for the attention point.

[0261] If the size calculation result of the object is recorded in therecording media 504 through the media recording/reproducing part 538, itis not necessary for the user to keep the measurement result in mind,but the measurement result can be fetched from the recording media 504,and be conveniently used by equipment (such as a personal computer)having the same function as the media recording/reproducing part 538capable of reading and writing the measurement result. Of course, themeasurement result may be superimposed on the color image picked up tobe preserved as an image.

[0262] In the foregoing example, the length of the object has beenmeasured, and it is also possible to measure a plurality of length fordetermining the area or volume on the basis thereof.

[0263] Further, another example of display and utilization of the pickupdata will be described.

[0264] As shown in FIG. 27, on the back of the camera, the display part518 and the touch panel 519 are piled up in a same position to display acolor image or a depth image which has been picked up, and areconfigured such that the user can denote the attention position(coordinate) in the image using the finger or a rod-shaped object.Through the use of this, it is possible to realize an object extractingcamera capable of obtaining an image obtained by extracting only anobject, on which the user focuses attention.

[0265]FIG. 28 is a block diagram showing the display/extractingoperation, and the object extracting camera has basically the sameconfiguration as the above-described shape measuring camera. A distanceimage and a color image which have been picked up are inputted into thecontrol part 537, and user's attention position designating coordinatesare also inputted into the control part 537.

[0266] The control part 537 can display a color image picked up on thedisplay panel 518 and extract only an object, at which the user aims,from a plurality of attention designating coordinates inputted by thetouch panel 519 and a depth image to display on the display panel 518for recording in the recording media 504.

[0267] With reference to FIG. 29, the description will be made of thisoperation.

[0268] First, the assumption is made that the user wishes to extract anobject 520. The user denotes a portion of the object 520 on the touchpanel 519. The control part 537 obtains the depth value of a portionincluding by this coordinate from the depth image, judges a portionhaving a depth continuously connected therewith as an object, at whichthe user aims, for displaying only the portion, and fills any portionsother than the portion with a certain specific color for displaying onthe display panel 518.

[0269] As regards judgment as to such a connected portion, so-calledimage processing can be performed that with a denoted coordinate as astarting point, the area will be expanded left, right, up or down as faras the depth value continuously varies and if there is any discontinuousportion in depth, the expansion will be stopped there.

[0270] A little longer distance than a distance between an object whichthe user wishes to extract and the camera, or a range of such a distancethat the user wishes to extract is denoted using the touch panel or thepush-button. The control part 537 displays a portion of a color imagehaving a closer value than a distance denoted by the value, or a colorimage included only in a portion within a range of the denoted distance,while the other portions are filled in with a certain specific color.Thus, they are displayed on the display panel 518, and are recorded inthe recording media 504.

[0271] In this manner, the camera is capable of judging only the object,at which the user aims, for extracting to display and record it. In thiscase, there is a possibility that depending upon the image processing,there arises a portion which is erroneously judged to be a foreground bya malfunction in spite of a background portion as shown in FIG. 30.

[0272] In this case, if the user denotes a portion (FIG. 29), in whichthe malfunction seems to have been done, by the touch panel 519 andcorrects the display result so that the portion is the background, itwill be possible to obtain a high-quality extracted color image for theobject. In this case, of course, the user may denote the portion whichhas been erroneously judged to be the background by the malfunction toperform a correcting operation so that this portion becomes aforeground.

[0273] By extracting a color image according to the distance using theinformation on the depth image as described above, it is possible toeasily obtain an image obtained by extracting only an object, at whichthe user aims, for preserving.

[0274] Also, in FIG. 28, an image memory is arranged within the controlpart 537, and an image to be reproduced and operated is once placed onthe image memory, whereby it is also possible to make the access speedfor images faster, or switch a plurality of images to high speed fordisplaying and operating.

[0275] According to the present embodiment as described above, it isalso possible to measure an actual size of an object without touchingit. Also, it is possible to realize a shape measuring camera and anobject extracting camera capable of easily extracting only an object, atwhich the user aims, on the basis of its depth information forpreserving.

[0276] In the fourth embodiment, the similar effect can be obtained evenif the housing for the shape measuring camera is constructed as shown inFIG. 21. More specifically, the configuration is arranged such that acamera part 9 [sic] containing an image pickup part 533 and a strobepart 508 containing first and second strobes 505 and 506 forming a lightsource are connected together by a joint 510 having a hinge-likeconfiguration in such a manner that the user can freely fold as shown inFIG. 21(a) and extend as shown in FIG. 21(b). During carrying, thecamera housing is small-sized in such a state as shown in FIG. 21(a),and during image-picking up, if it is extended as shown in FIG. 21(b)for use, the interval D between the lens 503 and the first and secondstrobes 505 and 506 in the light source can be made larger.

[0277] Also, the configuration can be arranged such that the lens andthe first and second strobes 505 and 506 are vertically arranged asshown in FIG. 21(c). In this case, in the depth image calculation, whilethe angles φ and θ are changes in the horizontal direction in theforegoing, the changes are only performed in the vertical direction, andthe depth image can be calculated by the similar calculation for theothers. In order to cause changes in the light intensity in the verticaldirection, the light source is configured by vertically-laidlight-emitting tubes as shown in FIG. 21(d).

[0278] In this case, even if the configuration is arranged such that ahousing 501 containing such a camera part as shown in FIG. 21 and ahousing 502 containing a light-emitting part have different thicknessfrom each other and can be fitted into each other in a superimposedmanner in a vertical direction as shown in FIG. 23, the similar effectcan be obtained. At this time, the light source part is constructed asshown in FIG. 23(d) [sic].

[0279] In the fourth embodiment, the similar effect can be obtained evenif the housing for a shape measuring camera is constructed as shown inFIG. 22. More specifically, the housing 517 containing the first andsecond strobes 505 and 506 in the light source part is made small-sized,and is connected to the camera housing 501 using the hingeconfiguration. During the use, the housing 517 is turned by the user tothereby expose the first and second strobes 505 and 506 in the lightsource part, whereby normally the housing can be made small-sized whilethe first and second strobes 505 and 506 in the light source part arenot exposed to thereby prevent them from being damaged due to anycareless contact, and at the same time, during image-picking up, theinterval D between these strobes and the lens can be made large.

[0280] In the fourth embodiment, although the light source isconstructed as shown in FIG. 2, even if the configuration is arrangedsuch that there is provided one light-emitting tube 529 and a liquidcrystal barrier 531 is placed in front thereof as shown in FIG. 24(a),it is possible to have the similar light pattern generating function.

[0281] In this case, if it is arranged that each light transmittanceportion is sequentially provided on the left side of the light-emittingtube 529 as shown in FIG. 24(b) and provided on the right-side thereofas shown in FIG. 24(c) in such a manner that the light-emitting tube 529sequentially emits light once at a time in the respective states, thenthe same light pattern as shown in FIG. 18 can be generated bysequentially causing one light-emitting tube to emit light twice withoutusing two light-emitting tubes as shown in FIG. 2.

[0282] This enables a small number of light-emitting tubes to emit lightas if light were emitted from the same position instead oflight-emitting patterns being emitted from positions a little deviatedvertically as shown in FIG. 2, and any measurement error in depth to bereduced.

[0283] This is because in FIG. 20, the position of an emitting point Qof the light pattern is deviated in the perpendicular direction in thepresent embodiment, whereas in this case, it is at the same position,and therefore a straight line PQ becomes a line, and less errors occurthan in the depth calculation using a straight line having differentvertical positions.

[0284] Also, in this case, the entire surface of a liquid crystalbarrier 532 [sic] is placed in a light transmitted state as shown inFIG. 24(d), whereby it can be utilized as a strobe for the camera forpicking up a normal two-dimensional image.

[0285] Also, according to the fourth embodiment, in the main bodies ofthe shape measuring camera and object extracting camera, the depth imageand color image are calculated, and recorded in the recording media. Asshown in FIG. 31, in the main body of the camera, image data picked upin synchronism with the first and second strobes 505 and 506 in thelight source is recorded in the recording media 504 through the mediarecording/reproducing part 538, and the image data is read out by ananalysis device 39 configured by a personal computer or the like toobtain desired analysis result by the distance calculation part 535 andthe color image calculation part 536. Thus, the object may be extractedor the shape may be measured using the display part 532.

[0286] The image data can also be transferred to the analysis device 539not through the recording media 504. For example, the camera body andthe analysis device 539 are connected together using existing datacommunication means. In the wire communication, parallel data interface,serial data interface and telephone circuits can be used. In the radiocommunication, optical communication, infrared-ray communication,portable telephone network communication and radio wave communicationcan be used. Further, the analysis result can be recorded in therecording medium.

[0287] In this case, the image pickup part 533 is a moving image pickingup video camera, and when the recording media 504 is a recording mediumsuch as tape, it is normally utilized as a camera for picking up a colormoving image. If the user lights a flash by pressing the push-buttononly when necessary and such an index signal as to allow only a video(such as a frame and a field) for the portion to be distinguished isstored in a recording medium in advance, the analysis device 539 iscapable of extracting only an image for a portion having an index signaland calculating the color image and depth image only for the portion foroutputting.

[0288] Also, in the fourth embodiment, the camera housing 501 has beenprovided with the light source part from the beginning, but it isconceivable to utilize a method to make only the light source partremovable in such a manner that it is in a small-sized andeasily-portable shape during normal color image picking up and that thelight source part is mounted for use only during depth image picking up.

[0289]FIG. 37(a) shows an external light source having such a structureas an external strobe device for photography, mounted thereon with sucha light source as shown in FIGS. 2 and 24. It is used by connecting itto the camera housing 501 as shown in FIG. 37(b) through a joint 549with the camera. FIG. 38 shows an example for such a light source foreliminating any shadow of the object as shown in FIGS. 35 and 36.

[0290] In FIG. 38(a), light sources are symmetrically arranged on bothsides of the joint 549. An aspect of the light sources connected to thecamera is shown in FIG. 38(b). Also, in FIGS. 37 and 38, the camera bodyis connected to the light sources using such a structure as a strobeshoe for film cameras, and a method of mounting using a tripod mountingscrew for cameras as shown in FIG. 39(a) is also conceivable.

[0291] In this case, it is configured such that a screw at the bottom ofthe camera housing 501 is used for mounting as shown in FIG. 39(b). Ifthe light sources are separated as such a removable external lightsource device, the camera becomes large only during depth image pickingup, and when used as a normal camera, it can conveniently become compactand lightweight.

[0292] Also, in the fifth embodiment, the user can denote a coordinateusing the touch panel in the configuration of FIG. 31, and other meanscan be used. When for example, a personal computer is used, an inputdevice such as a mouse or a keyboard can be used. In addition, a trackball, a switch, a volume and the like be can also utilized.

[0293] Also, in the fourth and fifth embodiments, the first and secondstrobes 505 and 506 in two light source parts are arranged at one sideof the image pickup part 533 as shown in FIGS. 13, 21, 22 and 23, and inthis case, when an object 540 and the background 541 are image-picked upin such an arrangement as shown in FIG. 32, light from the light sourcesis intercepted by the object 540 as shown in FIG. 33 to cause a shadow542 in an image to be obtained.

[0294] This portion is an area where light from the light sources doesnot reach, and is an area where any information as a distance imagecannot be obtained. In this case, light sources 543 and 544 having thesame configuration as the first and second strobes 505 and 506 in thelight sources are arranged at a side opposite thereto with the lens asthe center as shown in FIG. 34, whereby the area of this shadow can beeliminated. The method will be described below.

[0295] When the first and second strobes 505 and 506 in the lightsources are used, an area β is a portion where any information as adistance image cannot be obtained, and when the light sources 543 and544 are used, an area γ [sic] is a portion where any information as adistance image cannot be obtained. In the same manner as in theforegoing calculation, a distance image A and a color image A when thefirst and second strobes 505 and 506 in the light sources are used, anda distance image B and a color image B when the light sources 543 and544 are used, are independently calculated respectively in advance. Atthis time, in the respective images, the portions in the areas β and γ[sic] are judged to be portions having low luminance from the image dataobtained in advance.

[0296] Next, the distance images A and B are synthesized to newlygenerate a distance image free from any shadow area. This can berealized by adopting, if there exists an area which is not judged as theabove-described portion having low luminance in either of the distanceimages A and B, its value, and if neither of them is not the shadowarea, by using an average value of both image data.

[0297] The same is applicable to a color image, and if at least eitherof the color images A and B has data for other than the shadow portion,it is possible to synthesize a new color image free from any shadowarea.

[0298] In case of the foregoing configuration, it is necessary thatlight sources be arranged on the lateral sides or vertical sides of thelens. In this case, if the housing is configured such that housings 512and 513 containing light source parts on the lateral sides of the camerabody 511 are slid in opposite directions so as to be extended as shownin FIG. 35, the user can make it small-sized into the state shown inFIG. 35(a) for carrying during carrying, and extend it as shown in FIG.35(b) to take the base length D large during the use, making it possibleto prevent the depth image measuring accuracy from being degraded.

[0299] Also, the similar effect can be obtained even if theconfiguration is arranged such that the camera housing and the lightsources can be folded into three stages as shown in FIG. 36. Duringcarrying, they can be made small-sized by folding as shown in FIG. 36(a)for carrying, and during the use, the interval between the lens and thelight sources, the base length D can be taken large by extending them asshown in FIG. 36(b).

[0300] Also, in order to arrange the lens and the light sourcesvertically as shown in FIG. 21(c), the housings 512 and 513 of FIG. 35can be arranged on the vertical sides of the housing 11, and in FIG. 36,the housings 512 and 513 can be arranged on the vertical sides of thehousing 51 [sic].

INDUSTRIAL APPLICABILITY

[0301] As will be apparent from the foregoing description, according toa range finder device of the present invention, it is possible toprovide, at low cost, a highly reliable range finder device capable ofrealizing all by electronic operations and not including any mechanicaloperations.

[0302] Also, according to a range finder device of the presentinvention, it is capable of measuring a distance with excellent accuracyeven if light from the light source has a two-dimensional pattern.

[0303] Also, according to a range finder device of the presentinvention, it is capable of measuring a distance of an object in a placewhere light from the light source cannot be directly irradiated onto anobject.

[0304] Further, according to a camera of the present invention asdescribed above, a light source part having a simple configuration andhigh serviceability can be realized. Also, it has the effect that thedepth image measuring accuracy is not degraded because the distancebetween the camera lens and the light sources can be secured more thanseveral tens centimeters during the use although it is small-sizedduring carrying. Also, the length and size of the object can be simplymeasured without touching, and the size of an object can be known from acolor image once picked up. Also, it is possible to provide a shapemeasuring camera and an object extracting camera capable of simplyextracting an object to be aimed at from an image photographed.

1. A range finder device, for measuring, when a plurality of projectedlights having radiation patterns whose light intensity differsthree-dimensional space-wise are irradiated onto an object from alightsource on a time-sharing basis to image-pick up reflected light of saidprojected light from said object with a camera, a distance using thelight intensity of an image picked up, characterized in that, withrespect to each of a plurality of surfaces including the center of saidlight source and the center of a lens, there is obtained, in advance,relation between an angle of each projected light from said light sourceand light intensity in each surface, characterized in that, at the timeof actual distance measurement, light intensity of each pixel of saidcamera is measured, and on the basis of the light intensity thusmeasured, and relation between said angle and said light intensity on apredetermined surface corresponding to a coordinate position of saidpixel measured, there is obtained said angle corresponding to said lightintensity of the predetermined pixel thus measured, and characterized inthat, on the basis of these light intensity measured, said anglesobtained and further two-dimensional coordinate position information onsaid predetermined pixel on the image, a distance to said object iscalculated.
 2. The range finder device according to claim 1,characterized in that as said plurality of projected lights, there aretwo lights, and said projected lights are projected in differentdirections in a partly superimposed state position-wise with each other,and characterized in that relation between an angle of each projectedlight from said light source and light intensity is relation between theangle of each projected light from said light source and a ratio of eachlight intensity of said two projected lights at the angle.
 3. The rangefinder device according to claim 2, characterized in that said projectedlights are generated by arranging two light sources, each having apassive reflection plate provided behind said light source.
 4. The rangefinder device according to claim 1 or 2, characterized in that lightintensity of said image picked up is a differential value in image lightintensity between when said projected light exists and when it does notexist.
 5. The range finder device according to claim 1 or 2,characterized in that said object is irradiated at the same time withsaid plurality of projected lights, reflected light of said projectedlight from said object is picked up with said camera, and said imagethus picked up is made into an ordinary image.
 6. The range finderdevice according to claim 1 or 2, characterized in that said camera isset to exposure time of less than a light emitting period of time ofsaid projected light, whereby the influence of background light issuppressed.
 7. The range finder device according to claim 1 or 2,characterized in that said lens and said light source are arranged insuch a manner that a straight line between said lens and said lightsource runs in parallel to the horizontal axis of an image pickupelement surface.
 8. The range finder device according to claim 2,characterized in that said plurality of projected lights are generatedby a light source having a light transmission plate whose transmittancediffers two-dimensionally provided forward thereof.
 9. The range finderdevice according to claim 2, characterized in that said plurality ofprojected light is realized using such an optical element and a lightsource as to allow the light transmittance pattern to be switched. 10.The range finder device according to claim 3, 8 or 9, characterized inthat light intensity of projected light from said light source ismeasured in the absence of said passive reflection plate or lighttransmission plate to obtain a correction amount in advance, the lightintensity is corrected using said correction amount at the timeobtaining relation between an angle of each projected light from saidlight source and the light intensity, and at the time of actual distancemeasurement, light intensity measured is also corrected using saidcorrection amount.
 11. A range finder device, characterized bycomprising: a light source; a first optical fiber for guiding light tobe emitted from said light source; light distribution means for dividinglight guided by said first optical fiber into a plurality of courses; aplurality of second optical fibers whose one end is connected to saidlight distribution means, for irradiating said light divided from anaperture at the other end thereof onto said object; image pickup meansfor receiving reflected light of said irradiated light to acquire imagedata of said object; and distance calculation means for calculating adistance to said object on the basis of said image data, characterizedin that intensity of light to be irradiated onto said object from saidother end of each of said plurality of second optical fibers hasdistribution which is different on place.
 12. A range finder device,characterized by comprising: a light source; a first optical fiber forguiding light to be emitted from said light source; light branch meansfor dividing light guided by said first optical fiber into a pluralityof courses to irradiate onto said object; image pickup means forreceiving reflected light of said irradiated light to acquire image dataof said object; and distance calculation means for calculating adistance to said object on the basis of said image data, characterizedin that intensity of light, in any of those courses, to be irradiatedonto said object from said light branch means has distribution which isdifferent on place.
 13. A range finder device, characterized bycomprising: a plurality of light sources; a plurality of optical fibersfor individually guiding light to be emitted from said light sources onsaid object side to irradiate onto said object; image pickup means forreceiving reflected light of said irradiated light to pick up image dataof said object; and distance calculation means for calculating adistance to said object on the basis of said image data, characterizedin that intensity of light from any of the optical fibers to beirradiated onto said object has distribution which is different onplace.
 14. The range finder device according to claim 11 or 13,characterized in that there is provided a lens system arranged at thefront of an aperture of said optical fiber for irradiating light ontosaid object.
 15. The range finder device according to claim 11 or 13,characterized in that in order to obtain distribution which is differenton place of said light intensity, there is provided a light filter whoselight transmittance differs depending upon the place at the front of theaperture of said optical fiber for irradiating said light.
 16. The rangefinder device according to claim 12, characterized in that there isprovided a lens system arranged at the front of an aperture of saidlight branch means for irradiating light onto said object.
 17. The rangefinder device according to claim 12, characterized in that in order toobtain distribution which is different on place of said light intensity,there is provided a light filter whose light transmittance differsdepending upon the place at the front of the aperture of said lightbranch means for irradiating said light.
 18. The range finder deviceaccording to any one of claims 11 to 17, characterized in that said lenssystem is a collimator lens, a cylindrical lens, or a rod lens.
 19. Acamera for shape measuring or object extracting, having light-emittingmeans for irradiating an object with projected light having a specifiedradiation pattern, for picking up reflected light of said light-emittingmeans from said object to obtain a depth image using light intensity ofthe image picked up, characterized in that said camera has such astructure that a distance between said light-emitting means and animage-pickup lens is variable, and characterized in that the intervalbetween said light-emitting means and said image-pickup lens can betaken sufficiently large during the use.
 20. The camera according toclaim 19, characterized in that such a structure that a distance betweensaid light-emitting means and said image-pickup lens is variable isrealized by such a configuration that said light-emitting means and themain body including said image-pickup lens are relatively slidable, andduring the use, said light-emitting means and said main body are causedto slide in such a manner that they are spaced apart from each other,whereby the interval between said light-emitting means and said cameralens can be taken sufficiently large.
 21. The camera according to claim19, characterized in that such a structure that the distance betweensaid light-emitting means and said image-pickup lens is variable isrealized by said light-emitting means and the main body including saidimage-pickup lens being connected together by a hinge configuration, andduring the use, the hinge configuration between said light-emittingmeans and said main body is opened, whereby the interval between saidlight-emitting means and said camera lens can be taken sufficientlylarge.
 22. A camera for shape measuring or object extracting, havinglight-emitting means for irradiating an object with projected lighthaving a specified radiation pattern, for picking up reflected light ofsaid light-emitting means from said object to obtain a depth image usinglight intensity of the image picked up, characterized in that saidlight-emitting means has such a structure that shading plates eachhaving a hole are arranged in front of each of a plurality ofstraight-line shaped light sources arranged, and each hole in therespective shading plates is deviated from each other position-wise, andsaid plurality of light sources emit light on a time-sharing basis. 23.A camera for shape measuring or object extracting, having light-emittingmeans for irradiating an object with projected light having a specifiedradiation pattern, for image-picking up reflected light of saidlight-emitting means from said object to obtain a depth image usinglight intensity of the image picked up, characterized in that saidlight-emitting means is configured such that there is arranged, in frontof one light source, a light modulation device whose light transmittancediffers two-dimensionally and two-dimensional variation distribution ofthe light transmittance is switchable, and said light-emitting meansemits light plural number of times in response to switching of thedistribution of the light transmittance.
 24. A camera for shapemeasuring or object extracting, having light-emitting means forirradiating an object with projected light having a specified radiationpattern, for image-picking up reflected light of said light-emittingmeans from said object to obtain a depth image using light intensity ofthe image picked up, characterized by comprising: a plane display with atouch panel; and when a plurality of points in an object are denoted bythe user's touch operation while said picked-up image is being displayedon the touch panel, a distance calculation part for calculating anactual length between these points thus denoted from said depth imagedata.
 25. A camera according to claim 24, characterized in that saiddistance calculation part calculates, from length information on eachportion of said object obtained from said plurality of points denoted bythe user, an area or a volume of the object.
 26. A camera for shapemeasuring or object extracting, having light-emitting means forirradiating an object with projected light having a specified radiationpattern, for image-picking up reflected light of said light-emittingmeans from said object to obtain a depth image using light intensity ofthe image picked up, comprising: a plane display with a touch panel; andwhen a plurality of points in an object are denoted by the user's touchoperation on the touch panel while said picked up image is beingdisplayed on the touch panel, a distance calculation part forcalculating a diameter or a radius of a circle, or a length of acircular arc which passes said plurality of points denoted by the userfrom said depth image data.
 27. The camera for shape measuring or objectextracting, having light-emitting means for irradiating an object withprojected light having a specified radiation pattern, for image-pickingup reflected light of said light-emitting means from said object toobtain a depth image using light intensity of the image picked up,characterized by comprising: object extracting means for extracting onlyan object which exists less than a distance denoted by the user, or onlyan object which exists within a range of a distance denoted by the userby using said depth image picked up.
 28. The camera according to claim27, characterized in that a portion taken for the background orforeground by a malfunction in said extracting process is denoted bytouching said touch panel by the user, whereby said erroneous backgroundor foreground extracting operation can be corrected.
 29. The cameraaccording to any one of claims 24 to 27, characterized in that the userinputs a coordinate using a pen type pointing device instead ofoperating said plane display with a touch panel with the finger.
 30. Thecamera according to any of claims 24 to 27, characterized in thatinstead of operating said plane display with touch panel with thefinger, a cursor for representing its position on an image is displayedon a normal plane display, and the user inputs a desired coordinate byoperating a mouse or a push-button to thereby move the cursor position.31. The camera according to any of claims 19 to 30, characterized inthat a device for obtaining a depth image through the use of said imagedata picked up is capable of communicating with the main body includingits image-pickup lens through communication means.
 32. The cameraaccording to any of claims 19 to 31, characterized in that saidlight-emitting means can be separated from the main body including saidimage-pickup lens, and characterized in that said light-emitting meansis removed for use during normal video taking while during depth imagepicking up, said light-emitting means is mounted for use.
 33. A camerafor shape measuring or object extracting, having light-emitting meansfor irradiating an object with projected light having a specifiedradiation pattern, for image-picking up reflected light of saidlight-emitting means from said object to obtain a depth image usinglight intensity of the image picked up, characterized in that saidcamera serves dually as a video camera capable of picking up a motionimage to record it in a recording medium while said light-emitting meansdoes not emit any light, and characterized in that an index signal isadded, to image data picked up when said light-emitting means emitslight, and a depth image is calculated using only a specified image towhich said index signal has been added.
 34. The camera according to anyof claims 19 to 33, characterized in that said camera is capable ofgenerating also a color image at the same time in addition to said depthimage to output both said depth image and said color image.
 35. Thecamera according to claim 27, characterized in that said objectextracting part extracts a color image for only an object which existsless than a distance denoted by the user, or only an object which existswithin a range of a distance denoted by the user.